TS. Nguyễn Huỳnh Thông
BÀI GIẢNG CHỈ DÀNH CHO SINH VIÊN THEO HỌC LỚP
ĐỊA CHẤT KIẾN TRÚC & ĐO VẼ BẢN ĐỒ ĐỊA CHẤT
Đá là gì? Phân loại Đá?
Biến dạng là gì? (Definition)
Lực và ứng suất? (Stress & Strain)
Các giai đoạn biến dạng? (Stage)
Các yếu tố ảnh hưởng biến dạng? (Factor)
Đặc tính biến dạng dẻo-đàn hồi của Thạch quyển?
Đá là gì? Phân loại Đá?
Rock is a combination one or more minerals. The Earth's
outer solid layer, the lithosphere, is made of rock.
Deformation describes the transformations from some
initial to some final geometry
Deformation of a rock body occurs in response to a force
Lực và Ứng suất?
Force is Strength or energy as an attribute of physical
action (change the body) or movement (F = m*a)
Stress is a force applied over an area
Uniform stress = Pressure is a stress wherein the forces
act equally from all directions (X Y Z) (in fluid)
Confining stress = weight of overlying rocks is a uniform
If stress is not equal from all directions then we say that
the stress is a differential stress. Three kinds of
differential stress occur:
Tensional stress (or extensional stress), which
· Compressional stress, which squeezes rock; and
· Shear stress, which result in slippage and translation.
CÁC GIAI ĐOẠN BIẾN DẠNG
(Stages of Deformation)
Elastic Deformation -- wherein the strain is reversible.
Ductile Deformation -- wherein the strain is irreversible.
Fracture - irreversible strain wherein the material breaks.
We can divide materials into two classes that depend on
their relative behavior under stress
Brittle materials have a small or large region of
elastic behavior but only a small region of ductile
behavior before they fracture.
Ductile materials have a small region of elastic
behavior and a large region of ductile behavior before
Clockwise Rotation about the z-axis
Translation Parallel to the Y axis
Strain or Distortion
Homogeneous Deformation - Pure Shear
Homogeneous Deformation - Simple Shear
Heterogeneous or Inhomogeneous strain
Leads to distorted complex forms
CÁC YẾU TỐ ẢNH HƯỞNG
Temperature - At high temperature molecules and their
bonds can stretch and move, thus materials will behave
in more ductile manner. At low Temperature, materials
Confining Pressure - At high confining pressure
materials are less likely to fracture because the pressure
of the surroundings tends to hinder the formation of
fractures. At low confining stress, material will be brittle
and tend to fracture sooner.
Strain rate ?
BIẾN DẠNG GIÒN-DẺO CỦA THẠCH
CHƯƠNG 3: KIẾN TRÚC PHÂN LỚP
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